Ruth Chepngetich exceeded Ethiopian Tigst Assefa's female marathon global best by about 120 seconds at the Chicago Marathon in the year 2024.
Female long-distance world record-holder the athlete has been prohibited for 36 months after the runner acknowledged anti-doping rule violations.
Chepngetich was temporarily banned in the seventh month following a failed test for a banned substance - a banned diuretic used commonly as a masking agent - on March 14.
The athlete's accomplishments which occurred before that test - such as her global best performance of two hours, nine minutes and 56 seconds in Chicago in 2024 - will still stand.
The sports governing body had sought a 48-month suspension but the 31-year-old penalty was reduced to three years because she confessed to the infractions.
Nonetheless, the integrity unit will continue to investigate evidence from the athlete's phone which it found indicate "strong grounds that her positive test may have been intentional" - including communications from as early as 2022.
"This matter concerning the failed test for HCTZ has been resolved, but the AIU will continue to investigate the suspicious material found on Chepngetich's phone to ascertain if any further infractions have taken place."
When questioned in April by the integrity body, the marathoner, the first woman to complete a marathon in under 2:10, could not provide an reason for the failed test.
Although HCTZ has a lowest detectable limit of 20 nanograms per millilitre (ng/mL) in samples, the athlete's sample showed an approximate level of 3,800 ng/mL.
Small amounts of HCTZ under the detection threshold were also identified in a test collected from the runner two weeks earlier, on 28 February.
At a subsequent meeting on 11 July, Chepngetich was shown the aforementioned questionable proof obtained from her mobile. Meanwhile, accidental exposure had also been disproven by the AIU.
The athlete altered her story on 31 July, claiming that she had used her housemaid's medication - labeled as being the banned substance - after falling sick 48 hours prior to the failed test.
The unit had "serious reservations about the credibility of the revised account" and, in the framework of the sport's doping regulations, such "carelessness" is deemed "implied intention, for which an longer 48-month sanction is applicable".
An automatic one-year reduction was applied after Chepngetich admitted the anti-doping rule violations within the 20 days required.
The three-year ban started on April 19 - when Chepngetich agreed to a voluntary provisional suspension - with the competitor's results, awards, titles, participation and prize money from 14 March lost.
"No one is above the rules."
"While disappointing for those who had faith in this runner, this is how the system is designed to operate."
"Marathon organizers should be commended for jointly supporting anti-doping efforts able to revealing doping violations performed by top competitors in their races."
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